SNP Shot: Genomic Insights

Yao syndrome, previously known as NOD2-associated autoinflammatory disease, is characterized by recurring episodes of fever and widespread inflammation affecting multiple areas of the body, most notably the skin, joints, and digestive tract. Inflammation is a typical immune response to injury or foreign substances like bacteria. However, in individuals with Yao syndrome, the innate immune response, a part of the immune system, becomes abnormally activated, leading to fever and inflammation-related damage to tissues and organs. This abnormal activation classifies Yao syndrome as an autoinflammatory disease, which is different from autoimmune diseases because they involve different parts of the immune system.

The fever and inflammation episodes associated with Yao syndrome can persist for several days and reoccur every few weeks or months. During these episodes, most individuals experience reddened, inflamed skin areas known as erythematous patches or plaques, primarily on the face, chest, and back, but also potentially on the arms and legs. Joint pain and inflammation resembling arthritis are frequently observed, particularly in the legs, along with swelling in the ankles and feet. The gastrointestinal system is also affected by inflammation, resulting in attacks of abdominal pain, bloating, cramping, and diarrhea in over half of those affected. Approximately half of the individuals with this disease report dry eyes and dry mouth, described as "sicca-like" symptoms. Other possible signs and symptoms of Yao syndrome include mouth ulcers, chest discomfort, and enlarged glands.

Yao syndrome is generally diagnosed in adults. It's a chronic condition, meaning it's long-lasting, and episodes can continue to recur for many years.

Inheritance:

Yao syndrome's inheritance pattern is complex because it seems to be a multifactorial disease without a single genetic origin. Only a small fraction of affected individuals have a family history of the condition. Furthermore, many people who carry one or more NOD2 gene variants associated with Yao syndrome never develop the disease itself.